Whenever a medical device is used in a surgical setting, a risk of infection is created. The risk of infection dramatically increases for invasive or implantable medical devices, such as intravenous catheters, arterial grafts, intrathecal or intracerebral shunts and prosthetic devices, which create a portal of entry for pathogens while in intimate contact with body tissues and fluids. The occurrence of surgical site infections is often associated with bacteria that colonize on the medical device. For example, during a surgical procedure, bacteria from the surrounding atmosphere may enter the surgical site and attach to the medical device. Bacteria can use the implanted medical device as a pathway to surrounding tissue. Such bacterial colonization on the medical device may lead to infection and morbidity and mortality to the patient.
A number of methods for reducing the risk of infection associated with invasive or implantable medical devices have been developed that incorporate antimicrobial agents into the medical devices. Such devices desirably provide effective levels of antimicrobial agent while the device is being used.
WO 2003/043593 describes an antimicrobial system that uses an antimicrobial cationic surfactant derived from the condensation of fatty acids and esterified dibasic amino acids, as an antimicrobial activity enhancer, in combination with common antimicrobial agents. In particular, this reference describes the use of lauric arginate (LAE) in combination with 2,4,4′-trichloro-2′-hydroxy-diphenylether (triclosan), 3,4,4-trichlorocarbanilid (triclocarban), 2-phenoxyethanol, chlorhexidine salts, hexetidine and cetylpyridinium salts, for cosmetic formulations and preparations directed to avoid body odour and to provide oral care. This reference, however, is silent with respect to the use of LAE in connection with medical devices.
It would be beneficial to incorporate the antimicrobial cationic surfactant described above, either alone or in combination with common antimicrobial agents such as triclosan, triclocarban, 2-phenoxyethanol, chlorhexidine salts, hexetidine and cetylpyridinium salts, into an invasive or implantable medical device to reduce the risk of infection associated with such devices. Further, it is desirable to provide an antimicrobial composition where the release mechanism of LAE into the target environment is independent of the solubilization of the antimicrobial composition in the target environment, and that exhibits immediate activity upon contact with fluids in the human body.